BACKGROUND: Surgical aortic valve replacement (SAVR) is the conventional treatment in patients at low or intermediate surgical risk. Transcatheter aortic valve implantation (TAVI) is a less invasive procedure, originally developed as an alternative for patients at high or prohibitive surgical risk. METHODS: We conducted a health technology assessment of TAVI versus SAVR in patients with severe, symptomatic aortic valve stenosis at intermediate surgical risk, which included an evaluation of effectiveness, safety, cost-effectiveness, budget impact, and patient preferences and values. We performed a literature search to retrieve systematic reviews and selected one that was relevant to our research question. We complemented the systematic review with a literature search to identify randomized controlled trials published after the review. Applicable, previously published cost-effectiveness analyses were available, so we did not conduct a primary economic evaluation. We analyzed the net budget impact of publicly funding TAVI in people at intermediate surgical risk in Ontario. To contextualize the potential value of TAVI for people at intermediate surgical risk, we spoke with people who had aortic valve stenosis and their families. RESULTS: We identified two randomized controlled trials; they found that in patients with severe, symptomatic aortic valve stenosis, TAVI was noninferior to SAVR with respect to the composite endpoint of all-cause mortality or disabling stroke within 2 years of follow-up (GRADE: High). However, compared with SAVR, TAVI had a higher risk of some complications and a lower risk of others. Device-related costs for TAVI (approximately $23,000) are much higher than for SAVR (approximately $6,000). Based on two published cost-effectiveness analyses conducted from the perspective of the Ontario Ministry of Health, TAVI was more expensive and, on average, more effective (i.e., it produced more quality-adjusted life-years) than SAVR. The incremental cost-effectiveness ratios showed that TAVI may be cost-effective, but the probability of TAVI being cost-effective versus SAVR was less than 60% at a willingness-to-pay value of $100,000 per quality-adjusted life-year. The net budget impact of publicly funding TAVI in Ontario would be about $2 million to $3 million each year for the next 5 years. This cost may be reduced if people receiving TAVI have a shorter hospital stay (≤ 3 days). We interviewed 13 people who had lived experience with aortic valve stenosis. People who had undergone TAVI reported reduced physical and psychological effects and a shorter recovery time. Patients and caregivers living in remote or northern regions reported lower out-of-pocket costs with TAVI because the length of hospital stay was reduced. People said that TAVI increased their quality of life in the short-term immediately after the procedure. CONCLUSIONS: In people with severe, symptomatic aortic valve stenosis at intermediate surgical risk, TAVI was similar to SAVR with respect to the composite endpoint of all-cause mortality or disabling stroke. However, the two treatments had different patterns of complications. The study authors also noted that longer follow-up is needed to assess the durability of the TAVI valve. Compared with SAVR, TAVI may provide good value for money, but publicly funding TAVI in Ontario would result in additional costs over the next 5 years. People with aortic valve stenosis who had undergone TAVI appreciated its less invasive nature and reported a substantial reduction in physical and psychological effects after the procedure, improving their quality of life.